Alkylation catalyzed by binary mixtures of acid and ionic liquid

Abstract

An alkylation catalyst can include: a Brønsted acid ionic liquid; and a strong Brønsted acid that is not considered an ionic liquid. The Brønsted acid ionic liquid can be selected from the group consisting of [BMIm]HSO 4 , [MBSIm]HSO 4 , [MBSIm]OTf, [MPSIm]OTf, and [OMIm]HSO 4 or the like. In one aspect, the strong Brønsted acid is selected from the group consisting of sulfuric acid, hydrochloric acid (HCl), hydrobromic acid (HBr), HF, hydrogen iodide (HI), phosphoric acid, trifluoromethanesulfonic (triflic) acid. In one aspect, the strong Brønsted acid is present at more than about 50 wt % of the composition; however, the Brønsted acid can vary from about 10 wt % to about 99 wt %, more preferably about 20 wt % to about 90 wt %, and most preferably about 40 wt % to about 80 wt %.

1 . A alkylation catalyst composition comprising:
 an acid ionic liquid and   a strong Brønsted acid that is not an ionic liquid.   
     
     
         2 . The catalyst composition of  claim 1 , wherein the acid ionic liquid is a Brønsted acid ionic liquid is selected from the group consisting of [BMIm]HSO 4  (1-butyl-3-methylimidazolium hydrogen sulphate), [MBSIm] HSO 4  (1-methyl-3-(butyl-4-sulfonate) imidazolium hydrogen sulphate), [MBSIm]OTf (1-butyl-3-(butyl-3-sulfonyl)imidazolium trifluoromethanesulfonate), [MPSIm]OTf (1-butyl-3-(butyl-3-sulfonyl) imidazolium trifluoromethanesulfonate), and [OMIm]HSO 4  (1-octyl-3-methylimidazolium hydrogen sulphate). 
     
     
         3 . The catalyst composition of  claim 1 , wherein the acid ionic liquid is a protic ionic liquid. 
     
     
         4 . The catalyst composition of  claim 3 , wherein the protic ionic liquid includes a [Cation][Acidic Anion] selected from the group consisting of [Cation][HSO 4 ], [Cation][OTf], [Cation][Tf 2 N], [Cation][H 2 PO 4 ], [Cation][HPO 4 ] −2 , [Cation][HCO 3 ], [Cation][Acidic Inorganic Anion], [Cation][H 2 VO 4 ] 
     
     
         5 . The catalyst composition of  claim 1 , wherein the strong Brønsted acid is selected from the group consisting of sulfuric acid, HCl, HBr, HF, HI, phosphoric acid, trifluoromethanesulfonic (triflic) acid fluoro-sulfonic acid (HSFO 3 ), 1,1,1-trifluoro-N-(trifluoromethylsulfonyl)methanesulfonamide (H(Tf2N)), or the like. 
     
     
         6 . The catalyst composition as in  claim 1 , wherein the strong Brønsted acid has a Hammett number less than about negative ten (e.g., H 0 <−10). 
     
     
         7 . The catalyst composition of  claim 1 , wherein the strong Brønsted acid is present at more than about 50 wt % of the composition. 
     
     
         8 . The catalyst composition of  claim 1 , wherein the alkylation catalyst composition is substantially devoid of a weak or medium Brønsted acid and/or substantially devoid of a neutral ionic liquid, and/or substantially devoid of a Lewis acid ionic liquid. 
     
     
         9 . An alkylation reaction mixture comprising:
 a. the catalyst composition of  claim 1 ; and   b. an isoparaffin and an olefin.   
     
     
         10 . The reaction mixture of  claim 9 , wherein the olefin is selected from the group consisting of propylene, pentene, isobutylene, 1-butene, trans-2-butene, cis-2-butene, and derivatives thereof. 
     
     
         11 . The reaction mixture of  claim 9 , wherein the isoparaffin is selected from the group consisting of isobutane and isopentane 
     
     
         12 . The reaction mixture of  claim 9 , wherein isoparaffin:olefin (“I:O”) ratio is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, vice versa, or any range between a combination of the foregoing. 
     
     
         13 . A process for alkylating an isoparaffin comprising:
 providing a reaction mixture of  claim 9 ;   reacting the isoparaffin and an olefin in the presence of the alkylation catalyst;   forming an alkylated isoparaffin product; and   recovering an alkylated isoparaffin from the reaction mixture.   
     
     
         14 . The process of  claim 13 , wherein the olefin is selected from the group consisting of propylene, pentene, isobutylene, 1-butene, trans-2-butene, cis-2-butene, and derivatives thereof. 
     
     
         15 . The process of  claim 13 , wherein the isoparaffin is selected from the group consisting of isobutane and isopentane. 
     
     
         16 . The process of  claim 13 , wherein the reaction mixture has an isoparaffin/olefin (“I/O”) ratio of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, vice versa, or any range between a combination of the foregoing. 
     
     
         17 . The process of  claim 13 , wherein the reacting step occurs at a temperature of about −10° C. to about 50° C. 
     
     
         18 . The process of  claim 13 , wherein the reacting step occurs at a pressure of about 1 bar to about 60 bar. 
     
     
         19 . The process of  claim 13 , further comprising the step of recovering the alkylation catalyst from the reaction mixture. 
     
     
         20 . The process of  claim 13 , further comprising recycling the recovered alkylation catalyst into a second reaction mixture with fresh isoparaffin and olefin. 
     
     
         21 . The process of  claim 20 , further comprising recycling the recovered alkylation catalyst at least 5 times, and the reaction has a conversion of at least 50% in each cycle. 
     
     
         22 . The process of  claim 13 , wherein the reacting step is conducted in a batch, semi-continuous, or continuous manner. 
     
     
         23 . The process of  claim 13 , wherein the process has a C 8  selectivity which is greater than 50%, and C 8  selectivity is defined as the weight of C 8  products divided by the weight of all products. 
     
     
         24 . The process of  claim 13 , wherein the conversion of the limiting reactant is greater than about 90%. 
     
     
         25 . The process of  claim 13 , wherein the process has a trimethylpentane:dimethylhexane (“TMP:DMH”) ratio of greater than 4:1.